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RTAI release brings real-time add-ons to Linux 2.6

Apr 9, 2004 — by LinuxDevices Staff — from the LinuxDevices Archive

Project Leader Paolo Mantegazza reports that a test version of RTAI-3.1 is available for download, featuring real-time support for Linux 2.4.xx and 2.6.x. The release may represent the first implementation of real-time performance in the 2.6-series kernel, according to Mantegazza.

“Philippe did it, likely the first real time Linux-2.6,” said Mantegazza. Mantegazza earlier acknowledged XENOMAI developer Philippe Gerum's contributions to the RTAI 3.0 release.

Mantegazza says the new release represents “the death of the RTHAL way of working for ix86 machines. That alone sets a milestone in RTAI life. So RTAI i386 will work just on ADEOS and nothing else.”

The RTAI project has been working to replace the RTHAL (Real-Time Hardware Abstraction Layer) with ADEOS since running afoul of FSMLabs 5,995,745 US Patent in late 2001.

The release also contains bug fixes since the RTAI 3.0r3 release, according to Mantegazza.

“It should be remarked once more that RTAI is four things now (in alphbetical order): FUSION/RTAI/RTAILab/XENOMAI,” said Mantegazza, adding. “A particular note should be reserved to FUSION and I hope that Philippe will find time to advertise it a bit more in the near future. With FUSION RTAI has an almost continuous grading of real time requirements: soft (standard Linux), firm (Linux low latency), hard-1 FUSION, hard-2 LXRT, hard-3 kernel. In my opinion it is likely that a well matured FUSION will become a key player for many users.”

Mantegazza notes that the test release of RTAI 3.1 does not yet support the low latency option in Linux 2.6, nor symmetric multi-processing (SMP). Additionally, netrpc is not yet working.

“For the rest,” Mantegazza adds, “Most user space examples in showroom seem to be OK under UP, but examples involving kernel modules do not even compile. The core RTAI testsuite works well however in both kernel and user space.”

Mantegazza invites real-time Linux programmers to test and contribute to RTAI. “So give a try, have fun, and help to make it better,” he says.

The RTAI-3.1-test1 releases for 2.4.xx and 2.6.x are available for download from the RTAI homepage.

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